@function px2rem($px) {
  // 根元素字体为100px
  @return $px / 100 * 1rem;
}
html,
body {
  width: 100%;
  background-color: #fff;
  font-size: px2rem(30);
}

.code-box {
  display: flex;
  justify-content: space-between;
  margin: px2rem(300) px2rem(40);
  position: relative;
  box-sizing: border-box;
}

.code-box .code-item {
  width: px2rem(80);
  height: px2rem(80);
  line-height: px2rem(80);
  background-color: #fff;
  text-align: center;
  color: #000;
  font-size: px2rem(64);
  font-weight: bold;
  border-bottom: 1px solid rgb(209, 209, 209);
  transition: border 0.3s;
  box-sizing: border-box;
  margin: 0 px2rem(10);
}

.code-box .code-input {
  position: absolute;
  width: 100%;
  height: 100%;
  opacity: 0;
}

.active {
  border-bottom: 3px solid #333 !important;
}
